ZZ4 MPG Challenge II - The 1947 - Present Chevrolet & GMC Truck Message Board Network

gchemist · 07-22-2008, 07:54 PM

Vacationing from July 24-August 2nd. BADBOW is going on its second major trip. The ZZ4 now has 6000 miles since being installed. I may even hit the strip too! It is getting a custom hitch installed for the roll pan. I managed 18.5 MPG out of the ZZ4 after a few adjustments. I'm going to see if I can squeeze 19 and still do 70 MPH!!

Any suggestions for improvements? I'm thinking of backing off on timing to 8-9 degrees. Specs call for 10 BTDC at 800 RPMs. My problem is that my digital tach is not working. It works but I think the ground behind the dash is bad. If I have time, I hope to fix it during this trip.

What ya think?

View Poll Results: ZZ4 MPG Challenge II
17-18 MPG @ 70 MPH	4	28.57%
18+ MPG - better than the old 305!	3	21.43%
19+ MPG	1	7.14%
Forget milage, drive it like you stole it.	6	42.86%
Voters: 14. You may not vote on this poll

07-22-2008, 07:54 PM	#1
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	ZZ4 MPG Challenge II Vacationing from July 24-August 2nd. BADBOW is going on its second major trip. The ZZ4 now has 6000 miles since being installed. I may even hit the strip too! It is getting a custom hitch installed for the roll pan. I managed 18.5 MPG out of the ZZ4 after a few adjustments. I'm going to see if I can squeeze 19 and still do 70 MPH!! Any suggestions for improvements? I'm thinking of backing off on timing to 8-9 degrees. Specs call for 10 BTDC at 800 RPMs. My problem is that my digital tach is not working. It works but I think the ground behind the dash is bad. If I have time, I hope to fix it during this trip. What ya think? __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos Last edited by gchemist; 07-23-2008 at 11:13 AM.



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